* [Feature #18915] New error class: NotImplementedYetError or scope change for NotImplementedError (koic) * A new exception class `AbstractMethodError` inheriting from `ScriptError` has been designed. * Existing code may define an ...koic (Koichi ITO)
Thank you for taking the time to discuss this at the dev meeting. I realized that I had overlooked one issue. I found some existing code that defines `AbstractMethodError` with a superclass other than `ScriptError`. The impact on p...koic (Koichi ITO)
* [Feature #18915] New error class: NotImplementedYetError or scope change for NotImplementedError * `NotImplementedError` has frequently been used for a purpose different from its intended role, namely to indicate that a method is ex...koic (Koichi ITO)
I had an opportunity to discuss this with @matz and @shyouhei at Matsue RubyKaigi 12, held on June 6, 2026. Below is a summary of that discussion. - Leave the current `NotImplementedError` unchanged for now. - Introduce a new excepti...koic (Koichi ITO)
Although the example code comments indicate that it returns `false`, a non-matching result for `=~` is actually `nil`. ```ruby Foo.foo.blank? #=> false "foo".blank? #=> false ``` https://github.com/ruby/ruby/blob/v4.0.0-preview3/doc/...koic (Koichi ITO)
Based on the example, it appears that `foo.rb` and `main.rb` are expected to be in the same directory. Since Ruby 1.9, the current directory is not included in `$LOAD_PATH` by default. As a result, running `box.require('foo')` as shown i...koic (Koichi ITO)
This PR updates the fallback version for `Prism::Translation::ParserCurrent` from 3.4 to 4.0. Currently, the fallback resolves to `Parser34`, as shown below: ```console $ ruby -v -rprism -rprism/translation/parser_current -e 'p Prism::...koic (Koichi ITO)
ruby/setup-ruby is commonly used for development in OSS projects and real-world Rails applications. https://github.com/ruby/setup-ruby This is not specific to Ruby 4.0.0. There is often a delay between a Ruby release and the availabi...koic (Koichi ITO)
The following example code based on Ruby Box results in an unexpected error. https://github.com/ruby/ruby/blob/v4.0.0-preview3/doc/language/box.md#top-level-methods I'm not familiar with Ruby Box, but it seems that either the above d...koic (Koichi ITO)
koic (Koichi ITO)11:51 PM Ruby Misc #22107: DevMeeting-2026-07-09